The Interpreter, Lowy Institute for International Policy

Ballistic missile submarines (SSBNs) became the seagoing platform of choice for the deployment of strategic nuclear weapons by 1960, with the availability of submarine-launched ballistic missiles. Today there are five countries with operational SSBNs. The US, the UK, France and Russia all have a major part of their deterrent capability deployed on SSBNs. The only Asian country that currently has SSBNs in service is China, though their detailed operational status is not clear. India is in the process of operationalising its first SSBN; however it is not clear when a matching submarine-launched ballistic missile (SLBM) will be available. In light of the recent developments, the article concludes that the deployment of sea-based nuclear weapons will not destabilise the nuclear balance in the Indo-Pacific provided this is restricted to ballistic weapons with centralised launch authority and the requisite command and control structures. The situation would, however, become extremely unstable by the arming of ships and submarines with nuclear-tipped cruise missiles.